Funded by: Water Research Commission
April 2011 –March 2014
Project description
Pollution Research Group, Sasol Technologies and the WRC are cooperating on an investigation into the applicability of forward osmosis technology in treating inorganic brines. Currently, industries in South Africa and worldwide are seeking methods for lowering the cost and energy consumption involved in managing and treating brines resulting from desalination. For many years, Sasol Technology R&D has been researching desalination technologies and brine treatment processes, primarily using reverse osmosis plants, but the solution of low cost brine management remains an elusive target. For any new desalination technology to be commercially viable, it must offer significant improvements over reverse osmosis in measures such as energy costs, capital costs, water recovery rates, operability and maintenance requirements, water quality and product water costs.
Forward osmosis technology uses an osmotic pressure gradient instead of hydraulic pressure to transport water through the membrane. The process employs the natural phenomenon of osmosis, making the process less energy intensive and more cost effective. The primary advantage of forward osmosis is that it operates at low or no hydraulic pressure. Low energy requirement for forward osmosis technology makes it a green technology. Forward osmosis technology will potentially reduce brine discharges due to high recoveries associated with the technology, thus improving environmental impact of desalination technologies. Forward osmosis can contribute to sustainable supply of freshwater through preventing the degradation of water resources. The success in forward osmosis technology would bring access to clean water at affordable cost, thereby improving the quality of life for people.
The Evaluation of Forward Osmosis aims to improve the practical and quantitative fundamental knowledge of forward osmosis process in the country and throughout the world, by 1) evaluating the advantages, limitations and feasibility of using forward osmosis technology to concentrate various high ionic strength wastewaters, and 2) assessing the fouling characteristics of forward osmosis on various high ionic strength industrial streams which are known to be badly fouling.
Publications and reports
- Sitabule, E. N., 2013. Deliverable 3: Experimental Set Up Description. Report prepared for Water Research Commission.
- Sitabule, E. N., 2011. Deliverable 2: Survey of chemistry of Sasol concentrated streams (Desktop study using OLI Stream Analyzer Software). Report prepared for Water Research Commission.
- Sitabule, E. N., 2011. Deliverable 1: Literature review on forward osmosis technology. Report prepared for Water Research Commission.
- Overview of Forward Osmosis Technology as a potential energy efficient alternative for the treatment of concentrated brine streams. Presentation to the Management Group Technical Meeting, 20 October 2011.